优优班--学霸训练营 > 知识点挑题
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            • 1.

              设随机变量\(X~B(2,p)\),随机变量\(Y~B(3,p)\),若\(P(X\geqslant 1)=\dfrac{5}{9} \),则\(D\left( \sqrt{3}Y+1\right) =\)(    )


              A. \(2\)                                    
              B. \(3\)                                     
              C. \(6\)                               
              D. \(7\)


            • 2.

              一袋中有\(5\)个白球,\(3\)个红球,现从袋中往外取球,每次任取一个记下颜色后放回,直到红球出现\(10\)次时停止,设停止时共取了\(ξ\)次球,则\(P(ξ=12)\)等于(    )

              A.\(C_{12}^{10}{{(\dfrac{3}{8})}^{10}}{{(\dfrac{5}{8})}^{2}}\)
              B.\(C_{11}^{9}{{(\dfrac{3}{8})}^{9}}{{(\dfrac{5}{8})}^{2}}\dfrac{3}{8}\) 

              C.\(C_{11}^{9}{{(\dfrac{5}{8})}^{9}}{{(\dfrac{3}{8})}^{2}}\)
              D.\(C_{11}^{9}{{(\dfrac{3}{8})}^{9}}{{(\dfrac{5}{8})}^{2}}\)
            • 3.

              已知随机变量\(ξ~B(3,\dfrac{1}{3})\),则\(P(ξ=1)=(\)    \()\)

              A.\(\dfrac{2}{27}\)
              B.\(\dfrac{4}{27}\)
              C.\(\dfrac{2}{9}\)
              D.\(\dfrac{4}{9}\)
            • 4. 在三次独立重复试验中,事件\(A\)在每次试验中发生的概率相同,若事件\(A\)至少发生一次的概率为\( \dfrac {63}{64}\),则事件\(A\)恰好发生一次的概率为\((\)  \()\)
              A.\( \dfrac {1}{4}\)
              B.\( \dfrac {3}{4}\)
              C.\( \dfrac {9}{64}\)
              D.\( \dfrac {27}{64}\)
            • 5.

              若在一次测量中出现正误差和负误差的概率都是\( \dfrac{1}{2}\),则在\(5\)次测量中恰好出现\(2\)次正误差的概率是\((\)  \()\)

              A.\( \dfrac{5}{16}\)
              B.\( \dfrac{2}{5}\)
              C.\( \dfrac{5}{8}\)
              D.\( \dfrac{1}{32}\)
            • 6.

              位于坐标原点的一个质点\(P\)按下述规则移动:质点每次移动一个单位,移动的方向为向上或向右,并且向上、向右移动的概率都是\( \dfrac{1}{2}\),则质点\(P\)移动五次后位于点\((2,3)\)的概率是 \((\)  \()\)

              A.\(\left( \left. \dfrac{1}{2} \right. \right)^{5} \)
              B.\(C\rlap{_{5}}{^{2}}\left( \left. \dfrac{1}{2} \right. \right)^{5} \)​
              C.\(C\rlap{_{5}}{^{3}}\left( \left. \dfrac{1}{2} \right. \right)^{3} \)
              D.\(C\rlap{_{5}}{^{2}}C\rlap{_{5}}{^{3}}\left( \left. \dfrac{1}{2} \right. \right)^{5} \)
            • 7.

              某人射击一次击中目标的概率为\(0.6\),经过三次射击,此人至少有两次击中目标的概率为 (    )


              A.\(\dfrac{{81}}{{125}}\)
              B.\(\dfrac{{54}}{{125}}\)
              C.\(\dfrac{{36}}{{125}}\)
              D.\(\dfrac{{27}}{{125}}\)
            • 8.

              设随机变量\(X~B(2,p)\),随机变量\(Y~B(3,p)\),若\(P(X\geqslant 1)=\dfrac{5}{9}\),则\(D(\sqrt{3}Y+1)=\)

              A.\(2\)
              B.\(3\)
              C.\(6\)
              D.\(7\)
            • 9.

              将一枚硬币连掷\(3\)次,只有一次正面向上的概率是(    )

              A.\(\dfrac{3}{8}\)
              B.\(\dfrac{1}{2}\)
              C.\(\dfrac{1}{3}\)
              D.\(\dfrac{1}{4}\)
            • 10.
              已知某射击运动员,每次击中目标的概率是\(0.8\),则该射击运动员射击\(4\)次至少击中\(3\)次的概率为\((\)  \()\)
              A.\(0.85\)
              B.\(0.75\)
              C.\(0.8\)
              D.\(0.8192\)
            0/40

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